Automatic antidetonation system



July 10, 1 51 F. J. WIEGAND ETAL AUTOMATIC ANTIDETONATION SYSTEM 6Sheets-Sheet 1 Filed Nov. 6, 1943 INVENTORS FRANCIS J W/EGAND y EROLD F.PIERCE y 1951 F. J. WIEGAND ETAL 2,560,262

AUTOMATIC ANTIDETONATION SYSTEM Filed NOV. 6. 1943 6 Sheets-Sheet 2FRANCIS J W/EGAIVD y 1951 I F. J. WIEGAND ET AL 2,560,262

AUTOMATIC ANTIDETONATION SYSTEM Filed Nov. 6. 1943 6 Sheets-Sheet 5f'nont'uam: 60 MAM/FOLDPnsssun:

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INVENTOR FRA/vc/s .I W/EGAND EROLD F. PIERCE AFTNEY Patented July 10,1951 AUTOMATIC ANTIDETONATION SYSTEM Francis J. Wiegand, Ridgewood, andErold F. Pierce, Pines Lake, N. J., assignors to Wright AeronauticalCorporation, a corporation of New York Application November 6, 1943,Serial No. 509,336

25 Claims.

This invention relates to means for inhibiting detonation in an internalcombustion engine and is particularly directed to an anti-detonationfluid injection system permitting emergency high power engine operationwithout detonation.

The power available from an internal combustion engine is limited b theoccurrence of detonation in the engine combustion chambers. This isparticularly true of engines equipped with superchargers sincesupercharging not only increases the pressure of the combustion air ormixture and, therefore, the power output of the engine, but alsoincreases the temperature, thereby tending to cause detonation. That is,the usable amount of pressure boost obtainable from supercharging islimited by the occurrence of detonation within the engine. It is knownthat the addition of a cooling medium such as water into the combustionchamber reduces the temperature within the chamber, thereby permittingengine operation at higher intake manifold pressures without theoccurrence of detonation. The water or other anti-detonant used reducesthe temperature within the combustion chamber since evaporation of thewatertherein absorbs considerable heat. It is also old to introducespecial anti-knock fuels into the engine to inhibit detonation. However,the particular antidetonant used forms no part of the present invention.

It is an object of this invention to provide an improved system ofanti-detonation liquid injection and engine power control in order toprovide detonation-free high power engine operation. It is a furtherobject of this invention to provide an anti-detonant injection system inwhich the engine power is automatically increased substantiallysimultaneously with the injection of the anti-detonant within theengine. In addition, it is an object of this invention to provide ananti-detonant injection system for emergency engine power operation inwhich the engine power is automatically reduced when the supply ofanti-detonant is exhausted.

In order to increase the maximum amount of detonation-free poweravailable from an internal combustion engine, it is common practice toenrich the fuel-air ratio above a predetermined engine power. Apparentlythe extra fuel inhibits detonation. It is a further object of thisinvention to inhibit detonation at these higher engine powers byintroducing an anti-detonant into the engine instead of by increasingthe fuel-air ratio.

A further object of this invention consists in the provision of anengine power regulator which employed in the system of Fig. 1.

Fig. 3 illustrates the system of Fig. 1 as applied to an aircraft engineequipped with a turbosupercharger,

Fig. 4 is a modification of the fluid control valve illustrated inFigures 1 and 3 for controlling the discharge of anti-detonant into theengine,

Figs. 5, 6, and '7 disclose modified arrangements of the power controlvalve illustrated in the systems of Figures 1 and 3 for respectivelycontrolling the operation of their boost or turbo-regulators,

Fig. 8 illustrates a further application of an anti-detonation injectionsystem to an internal combustion engine,

Fig. 8A illustrates a modification of the system of Fig. 8; and

Fig. 9 is a further modification in which a pump is used to dischargethe anti-detonant into the engine.

Referring to Fig. 1, a conventional aircraft engine 50 is provided witha carburetor II and a carburetor adapter I2 which comprises a ductextending from the carburetor and communicating with the intake side ofa supercharger Id. The supercharger discharges combustion air or mixtureinto an annular manifold l5 from which it is distributed to the variousengine cylinders IS. A so-called boost pressure regulator l8automatically operates to control the carburetor throttle formaintaining a desired manifold pressure. The details of the boostregulator form no part of the present invention and any suitableregulator may be used.

As illustrated in Fig. 2, the regulator l8 may comprise a bellows 20which is responsive to the engine intake manifold pressure through thepipe connection 22 and a tension spring 24, connected at its lower endto the bellows 20 and at its upper end to a rod 25, opposes expansion ofthis bellows. The bias of the spring 24 is adjustably controlled throughthebell crank control lever 26 pivotall connected to the rod 25 toprovide manual control of the boost regulator. Movement of the bellows20 is transmitted to a pilot valve 28 of a fluid motor 88. An increasein the engine intake manifold pressure or a reduction in the tension ofthe spring 24 by counterclockwise movement of the control lever 26 (Fig.

i 2) results in an expansion of the bellows 28 to deflect the pilotvalve 28 in a downward direction. Thereupon fluid pressure is admittedfrom the pressure supply line 32 through passage 34 to the lower end ofthe fluid motor .and simultaneously the upper end of the fluid motor isconnected to a drain passage 36 through the passage 38, therebyoperating the fluid motor piston 40 in an upward direction to provide aclosing adjustment of the carburetor throttle 42. Similarly, a reductionin the engine manifold pressure or an increase in the tension of thespring 24 when lever 28 is moved clockwise results in a downwardmovement of the piston 40 to provide an opening adjustment of thecarburetor throttle. As illustrated, the piston 48 is connected to thecarburetor throttlev 42 by means of a sliding pivoted connection with alever 4| having a fixed pivot at one end and pivotally connected at itsother end to one end of a lever 43, the other end of which is pivotallyconnected to an arm 45 rigid with the carburetor throttle 42. Thebellows 20 expands against an evacuated bellows 44; that is, against afixed absolute pressure whereby the boost regulator operates to maintainthe desiredmanifold pressure regardless of the pressure of theatmosphere. The engine and boost regulator structure so far described isconventional.

The extent to which the engine intake manifold pressure may be increasedis limited by detonation of the engine at high manifold pressures. It isknown that the introduction of water or other anti-detonant having ahigh latent heat of vaporization considerably reduces the temperaturewithin the combustion chamber because of the quantity of heat absorbedin vaporizing this liquid in the combustion chamber. This reduction oftemperature permits engine operation at higher intake manifold pressureswith a corresponding increase in engine power. The provision of means toinject such an anti-detonant into the combustible mixture isparticularly desirable in military aircraft in order to provide theextra power necessary to meet the various emergencies that may arise.

Referring back to Fig. 1, a tank 48 for water or other anti-detonant isconnected through a metering valve 48 and a conduit 49 to a dischargenozzle 50 (more than one discharge nozzle, if desired, may be provided)which is adapted to discharge water or other anti-detonant into theengine induction system at the carburetor adapter l2 under the controlof the pilot, as hereinafter described. The upper level of the water inthe tank 48 is subjected to engine intake manifold pressure through theconduit 52, restricted orifice 54, and the spring-biased check valve 56,whereby the manifold pressure provides the force discharging the waterthrough conduit '49 and nozzle 50 when the valve48' opens. That is, theanti-detonant is discharged through the nozzle 50 by the differentialpressure between the engine intake manifold pressure and the pressure inthe carburetor adapter 12. At this point it should be noted that a pumpcould be used to provide the differential pressure for discharge of theanti-detonant, as hereinafter described, instead of using the enginemanifold pressure. The metering valve 48 is controlled by an evacuatedbellows 58 externally subjected to the engine intake manifold pressureby conduit connections 52 and 68. A spring 52-biases the valve 48 in aclosing direction. With this arrangement the metering valve 48 isadapted to open when the engine intake manifold pressure exceeds apredetermined value, whereupon water or other anti-detonant is injectedinto the combustible mixture through the nozzle 50, the rate ofdischarge of the anti-detonant depending upon the magnitude of themanifold pressure acting against the bellows 58 controlling the meteringvalve 48, that is, upon the engine power.

A power control valve 84 is arranged to effect operation of the boostregulator l8 to increase the engine manifold pressurewhen water or otheranti-detonant is discharged through the conduit 49 upon the occurrenceof the aforementioned predetermined manifold pressure. This valvecomprises a movable valve element 68 supported by a diaphragm 88. Theupper side of this diaphragm is connected to the conduit 49 while theunderside of the diaphragm is vented, preferably to the carburetoradapter l2 through conduit 69, and in addition-a spring It acts againstthe valve to bias the valve in a closing direction.

A restricted orifice I2 is located in a manifold pressure connection tothe boost regulator and a vent line 14 extends from this orifice to thenormally closed valve element 66. When the valve 86 is closed, the boostregulator operates in its normal manner to maintain the engine intakemanifold pressure as set bylthe control lever 26. When the valve '88 isopened the bleed line 14 is vented through a restricted orifice 18,thereby lowering the pressure in the bellows 20 of the boost regulator.The boost regulator, thereupon, operates to adjust the carburetorthrottle to increase the engine intake manifold pressure in order torestore the pressure in the bellows 28. In other words, the valve 66,when opened, provides a restricted vent in the manifold pressureconnection to the boost regulator, thereby having the same eifect onthis regulator as a reduction in the manifold pressure, whereupon theregulator operates to increase the manifold pressure.

The effect of the vent bleed through the line 14 increases with altitudebecause of the decrease in atmospheric pressure with altitude..Therefore, with valve 88 open the boost regulator operates to maintaina higher engine intake manifold pressure at high altitudes than at lowaltitudes. Accordingly, a safety spring-biased check valve 18 is shuntedaround the restricted orifice 12 in order to limit the pressure dropacross this orifice produced by the flow therethrough when the valve 68is opened. Thus, the checkvalve 18 provides an upper limit to thepressure drop which can be produced across the restricted orifice 12when the valve 68 is opened.

The operation of Fig.1 is as follows;

In normal operation the .pilot controls th engine power by operation ofthe boost regulator control lever 26 and, as lon as the regulator is setto maintain an intake manifold pressure below a certain value, theanti-detonant injection system remains inoperative. Should an emergencyarise requiring extra power, the control lever 26 is thrown to anemergency high power position, whereupon the boost regulator adjusts thecarburetor throttle for a somewhat higher manifold pressure. Thisincrease in the manifold pressure is sufficient to open the meteringvalve 48, whereupon the manifold pressure against the water or otheranti-detonant in the tank 46 operates to force the anti-detonant throughthe conduit 49 and nozzle 50 into the air or combustion mixture in frontof the supercharger. In addition, the pressure in the conduit 49 istransmitted to the upper side of the diaphragm 68 to open the powervalve 66. This valve, when opened, provides a restricted vent for themanifold pressure connection to the boost regulator, whereupon the boostregulator automatically operates to adjust the carburetor throttle foran emergency high intake manifold pressure to provide the necessaryemergency power. The water or other anti-detonant enters the combustionchambers of the engine with the combustion mixture to inhibit detonationat this high engine power. After the tank 46 is empty, the sprin bias onthe nozzle valve 50 is such that the manifold pressure quickly bleedsout from the tank through the nozzle, whereupon the valve 66 closes thevent line 14 to the boost regulator. That is, although a given pressure,whether exerted by a gas or a liquid, will open the nozzle valve 50 tothe same extent, the same nozzle valve opening inherently will offermuch less restraint to the discharge of gases therethrough. Accordingly,when the supply of anti-dentonant liquid is exhausted, the manifold gaspressure bleeds out through the nozzle faster than could theanti-detonant liquid and faster than the manifold gas pressure can enterthrough the restricted orifice 54. Ac-.

cordingly, the nozzle 50 practically closes, thereby maintaining arelatively small back pressure therethrough. Thus when the supply ofliquid anti-detonant becomes exhausted, the pressure quickly falls offin line 49 and the valve 66 closes. Obviously, in order to facilitatethe escape of manifold gas pressure from line 49, the nozzle valve 50could be provided with a small bleed opening therethrough which' wouldbe small enough to prevent unrestricted discharge of the liquidanti-detonant therethrough, but would permit the manifold pressure gasesto readily escape therethrough into the carburetor adapter from line 49whenthe nozzle valve 50 was otherwise closed. The regulator, thereupon,operates to reposition the carburetor throttle for a decreased enginepower. Similarly, if there is no water or other anti-detonant in thetank 46 when the control lever 26 is thrown to the emergency powerposition, the fluid valve 48 will open as described above but, becauseof leakage through nozzle 50, the pressure in the conduit 49 will beinsuflicient to open the power valve 66 and, as a result, there is noincrease in the power of the engine above its normal detonationfreepower range. In other words, although the nozzle 50 offers considerablerestraint to the flow of water or other anti-detonant there through,this nozzle offers very little restraint to the escape of manifoldpressure when no water is present whereby, in the latter case, themanifold pressure bleeds out through the nozzle 50 faster than it issupplied to the tank 46 through the restricted orifice 54. Therefore,with water or other anti-detonant in the tank 46 when the metering valve48 opens the pressure in the conduit 49 is substantially equal to theengine manifold pressure plus the head of water in the tank, but with nowater or other anti-detonant in the tank the pressure in the conduit 49is considerably less than the intake manifold pressure.

With the above system the pilot may obtain the normal range of powerfrom the engine by control of the boost regulator in the conventionalmanner. If emergency power is desired the boost regulator is set for ahigher engine power output, whereupon the increase in manifold pressurei operable to effect water ejection into the induction system.Substantially simultaneously therewith a vent is opened in the manifoldpressure connection to the boost regulator, whereupon the boostregulator operates to further increase the engine manifold pressure tofurnish the emergency power. The injection of the water into thecombustion air or mixture inhibit detonation in the combustion chamberat this emergency power. However, if the supply of water or otheranti-detonant is exhausted, the system is inoperative to provide theemergency power; or if the supply of water or other antimal enginepower.

detonant becomes exhausted during the emergency high power operation thesystem automatically operates to reduce the engine power to preventdetonation. These latter functions are safety features which preventoperation of the engine above its normal detonation-free power rangewhen the supply of anti-dentonant is exhausted.

As a typical example, the manual control lever '26 of the boostregulator l8 may be provided with a stop setting, indicated by thedashed line 26 in Figure 2, for an engine manifold pressure of 45" of Hgcorresponding to the maximum nor- The control lever 26 is also providedwith an emergency stop setting, indicated by the dashed line 26" inFigure 2, for a manifold pressure of 47" of Hg, at which pressure themetering valve 48 opens. Also, the vent bleed, when open through line14, valve 66, and orifice 16, may be designed to provide a pressure dropof 8" of Hg across the restricted orifice 12. With this arrangement,when the boost regulator is set to the emergency stop corresponding to,the manifold pressure of 47" of Hg, the engine manifold pressure willrise to this value, whereupon the metering valve 48 opens and the antidetonant is discharged into the engine induction system. Simultaneously,the power valve 66 opens to provide a pressure drop of 8" of Hg to theboost regulator l8 across the restricted orifice 12. In response to thispressure drop, the boost regulator immediately opens the carburetorthrottle to increase the engine manifold pressure from 47 of Hg to 55"of Hg in order to compensate for this 8" of Hg pressure drop. Thus, inthis example it is seen that with the aforedescribed anti-detonantinjection system the maximum value of detonation-free engine power isincreased from an engine power output corresponding to an engine intakemanifold pressure of 45" to 47 of Hg to a considerably higher enginepower corresponding to an engine intake manfold pressure of 55" of Hg.When the supply of anti-detonant is exhausted, the vent line 14 isclosed by the valve 66 so that the full manifold pressure of 55" of Hgis applied to the boost regulator which is still set for a manifoldpressure of 47" of Hg. Accordingly, the regulator immediately operatesto restore the engine manifold pressure to 47" of Hg, therebyautomatically avoiding engine detonation.

Fig. 3 discloses an anti-detonation injection system similar to theabove-described anti-detonation injection system but applied to aninternal combustion engine equipped with a turbo-supercharger. Thesystems of Figs. 1 and 3 are essentially the same and similar parts havebeen designated with similar numerals. In this modification the exhaustfrom the engine 88 is discharged into an annular exhaust manifold 82 andthence into an annular nozzle box 84 from which the combustion gases aredischarged against the buckets 86 of a turbine wheel 88. This turbinewheel is drivably connected to the impeller of a supercharger 92 whichsupplies compressed air to the carburetor 94. From the carburetor, thecombustion air or mixture passes through the carburetor adapter 86 andmay be further compressed by an engine-driven supercharger 98 whichdischarges into the annular intake manifold I88 from which thecombustion air or mixture is fed to the various engine cylinders.

The turbo-supercharger 98, 92 is equipped with a regulator I8 which issimilar to the boost regulator I8 system of Fig. 1 except that it isresponsive to the turbine nozzle box pressure through the conduit I82and controls the turbine waste gate I04. Although the turbo-regulator I8as illustrated is controlled in response to changes in the nozzle boxpressure, the invention obviously is not limited to this arrangement andmay be used with other conventional arrangements, e. g., in which theturbo-regulator I8 is controlled by the engine intake manifold pressureor by the carburetor inlet pressure. That is, line I82, instead of beingconnected to the turbine nozzle box 84, instead may be connected to theengine intake manifold or to the inlet side of the carburetor. Thedetails of constructicn of the turbo regulator I8 are similar to that ofthe boost regulator illustrated in detail in Fig. 2 but any suitableregulator may be substituted therefor.

An anti-detonant supp tank 48 is subjected to engine manifold pressurethrough a conduit 52, a restricted orifice 54, and a spring-biased checkvalve 56. An evacuated spring-biased bellows 58 is responsive to theengine intake manifold pressure through the lines 52 and 88 to open themetering valve 48 when the manifold pressure exceeds a predeterminedvalue. When the valve 48 is opened the engine manifold pressure forcesthe water or other anti-detonant from the tank 46 through the conduit49, the nozzle 58, and into the engine induction system in front of theengine-driven supercharger. A power control valve 68 is operated by adiaphragm 68 subjected on one side to the pressure in the conduit 48 andon the other side to the pressure in the carburetor adapter 86. Thepower valve 88. when opened, provides a restricted venting opening I8for the nozzle box pressure controlling the turbo-regulator through theorifice l2, whereupon the regulator operates to adjust the waste gate ina closing direction to increase the engine intake manifold pressure. Inaddition, a safety check valve I8 is provided to limit the the pressuredrop across the restricted orifice I2, as previously'explained inconnection with Fig. l.

The operation of Fig. 3 is essentially the same as Fig. 1 except thatthe power valve 66 in Fig. 1 acts on the boost regulator to effect theopening adjustment of the carburetor throttle to increase the engineintake manifold pressure, while in Fig. 3 the power valve 68 acts on theturboregulator to eifect a closing adjustment of the turbine waste gateto increase the engine intake manifold pressure. The operation of theantidetonation liquid injection systems of Figs. 1 and 3 are otherwisesimilar.

described in connection with the- At this point it should be noted thatalthough the invention has been described and illustrated, in Figures 1and 3, in connection with a supercharged internal combustion engine, theinvention obviously is not so limited but can readily be applied to anyinternal combustion engine whose power output is limited by detonationwhether or not the engine has a supercharger in its induction system.

Fig. 4 illustrates a modification of the water flow valve 48 of Figs. 1and 3. In this modification the movable valve element I84 is supportedby the diaphragm I88, subjected on the one side to engine intakemanifold pressure through the line 52 and on the other side to thedischarge pressure of the valve. In additio a spring I88 biases thevalve to its closed position. The discharge side of the valve I84 isconnected by conduit II2 to a nozzle II8 which is adapted to dischargewater or other anti-detonant from the tank 45 into the carburetoradapter, as in the systems of Figs. 1 and 3, when the valve I84 isopened. The valve I84 is designed to open when the manifold pressurereaches a predetermined value and the nozzle H8 is set to maintain aback pressure lower than the manifold pressure required to open thevalve I84. Therefore, even when the valve I84 opens, the pressure abovethe diaphragm I88 will be less than the pressure below the diaphragm sothat the valve I84 will remain open. If the nozzle II8 dischargesagainst a constant pressure in the carburetor adapter, thevalve I84 willhave a fixed position regardless of the atmospheric pressure. However,if the carburetor adapter pressure decreases somewhat with altitude,then the valve I84 :will open further at the higher altitudes,

thereby supplying more water at the higher altitudes. This is desirablebecause, at a constant engine intake manifold pressure, the engine powerincreases with increase in altitude.

The fluid valve I84, Fig. 4, has a fixed open position for a givenmanifold pressure regardless of the altitude if the carburetor adapterpressure is maintained substantially constant or, if the carburetoradapter pressure decreases with increase in altitude, the extent towhich the valve I84 opens will also increase with altitude. This valveI84 may be substituted in either Figs. 1 or 3 and has the advantage thatno evacuated bellows 58 is necessary.

Figs. 5 and 6 disclose modifications of the power control valve. Both ofthese modifications may be used either with the system of Fig. l or thatof Fig. 3, although they have been illustrated and are hereinafterdescribed in connection with the system of Fig. 1. In Fig. 5 themetering valve 48 is responsive to the engine intake manifold pressurethrough the lines 52 and 68 for opening this valve when the manifoldpressure exceeds a predetermined value. When the valve 48 is open, themanifold pressure acting on the anti-detonant in the tank 46 forces theantidetonant through the valve 48, line 48, and through the dischargenozzle mounted on the carburetor adapter. The power control valve I28 isspring-urged toward closed position and is connected to a diaphragm I22communicating on the one side to the water supply tank 48 and on theother side this diaphragm is vented through a restricted orifice I24.The valve I28, when open, provides a vent bleed for the pressureconnection to the manifold pressure regulator through the line 14, valveI28, and restricted The power control valve I 20 may be designed to openwhenever engine intake manifold pressure is applied to the water orother anti-deto nant in the tank 46. With this arrangement the valve I20normally unbalances the manifold pressure regulator I8 so that thispressure regulator maintains a higher value of engine power for a givensetting of the regulator if water or other anti-detonant is present thanif the supply of anti-detonant is exhausted. When the manifold pressureregulator is set to effect an increase in the engine power above itsnormal power range, the resulting increase in manifold pressure operatesto open the metering valve 48, where: upon water or other anti-detonantis discharged into the engine induction system. The discharge ofanti-detonant into the engine induction system permits an increase inthe engine power above its normal range without causing detonation. Whenthe supply of water or other anti-detonant is exhausted the pressure inthe supply tank 45 quickly drops as previously described, therebyeffecting closure of the power control valve I 20 and its associatedrestricted orifice I24 in the vent bleed connection to the manifoldpressure regulator. With this closing of the vent bleed connection tothe manifold pressure regulator, the regulator operates to reduce themanifold pressure and the power output of the engine. That is, thefunction of the power control valve is to prevent emergency high powerengine operation when the supply of water or anti-detonant is exhausted;or if this supply should become exhausted during high power operation,the power control valve functions to reduce the engine power.

The power control valve I20, instead of opening whenever the manifoldpressure is applied to the liquid in the tank 46, may be designed toopen ata predetermined value of manifold pressure corresponding to themaximum value of detonationfree engine power available without theaddition of an antidetonant. With this arrangement, whenever themanifold pressure regulator is set to maintain a pressure above thispredetermined value, the valve I 20 opens to unbalance the manifoldpressure regulator and this regulator thereupon operates to increase themanifold pressure for emergency high power operation. The metering valve48 is adapted to open substantiall simultaneously wtih this opening ofthe power valve I 20, or the increase in manifold pressure effected bythis opening of the power valve may cause th metering valve 48 to open,whereupon the anti-detonant is discharged into the engine inductionsystem. When the supply of anti-detonant is exhausted, the pressure inthe tank 46 quickly drop thereby closin power control valve I20 and itsassociated restricted orifice I 24. With this closing of the vent bleedconnection to the manifold pressure regulator, the regulatorautomatically operates to reduce the manifold pressure for normal engineoperation. In other words, when emergency power is desired, the engineoutput is increased in the normal manner by controlling the manifoldpressure regulator to the point where the power control valve opens toautomatically effect a further increase in the manifold pressure, and atthe same time metering valve 48 opens to effect introduction of anantidetonant into the engine induction system. In

addition, when the anti-detonant supply is exhausted, the pressureimmediately drops within the tank 46, whereupon the valve I20 closes andthe manifold pressure regulator repositions itself 10 to reduce themanifold pressure to its normal value.

The system of Fig. 6 is similar to Fig. 5 except that a pair of seriallyconnected valves I26 and I28 hav been added to assist, if necessary, inquickly effecting a reduction in the engine power when the water supplyis exhausted. The added valve I26 comprises a movable gate-type valveelement carried by the power valve I20. The power valve I20, with itsoperating diaphragm I 22 and associated vent I24, is connected inparallel with the serially disposed valves I26 and I 28. The valve I26is adapted to open when the power valve I 20 closes and vice versa.Accordingly, when the power control valve I20 closes the pressureregulator bleed connection through restricted orifice I24, the valve I26is open, and if the valve I28 is also open, then manifold pressure isadmitted through the serially disposed valves I26 and I28 from lines 52and I30 to the manifold pressure regulator. The valve I28 is similar tothe valve 48 and this valve is adapted to open when the manifoldpressure exceeds the predetermined value at which the valve 48 opens.

During emergency high power engine operation the power valve I20 andwater metering valve 48 open as described in connection with Fig. 5

and, in addition, with valve I20 open, valve I26 is closed and the valvI28, connected in series therewith, is open. When the water supply isexhausted, the power valve I 20 closes, thereby opening the valve I26.Manifold pressure is thereupon admitted through lines 52 and I 30 andthrough the serially connected valves I26 and I 28 directly to themanifold pressure regulator to quickly effect a reduction in themanifold pressure. Normal operation of the pressure regulator isrestored as soon as the resulting reduction in manifold pressure effectsa closin of the valve I28. In the absence of the provision of the valvesI 26 and I28, when the water supply is exhausted and the vent bleedconnection to the manifold pressure regulator is closed by the powercontrol valve, it is necessary for the manifold pressure to build upthrough the restricted orifice I2 before the pressure regulator caneffect a reduction in the manifold pressure. However, with the valvesI26 and I28 operable as described, when the pewer control valve closesthere is no such delay, since the manifold pressure is immediatelyplaced in unrestricted communication with the regulator through valvesI26 and I28.

In Fig. 6 the valves I26 and I28 in effect have been added to the powercontrol valve I 20 unit illustrated in Fig. 5. It seems clear thatvalves I26 and I28 could be added to the power control valve unit 64 ina similar manner and for the same purpose; namely, to effect a quickreduction in the engine power when the supply of anti-detonant isexhausted.

With the conventional manifold pressure regulator illustrated in Figs. 1and 2, the regulator operates to maintain a constant manifold pressureregardless of variations in atmospheric pressure. However, the engineexhaust back pressure decreases with altitude and, therefore, with aconstant engine intake manifold pressure, the engine power will increasewith altitude. Accordingly, in order to maintain a constant engine powerfor a given setting of the regulator, the regulator should operate tomaintain a decreasing manifold pressure with increasing altitude.

In the case of a turbo-supercharger installation, the conventional turbowaste gate regulator operates to maintain a constant turbine nozzle boxpressure. hausts into the atmosphere, the power absorbed by the turbinewill increase with altitude because addition to the power control valvewhich is' operative to so adjust the pressure regulator with variationsin altitude in order to maintain a constant engine power for a givensetting of the regulator. This modification has been illustrated inconnection with Fig. 1 but, as will appear, this modification is equallyapplicable to the system of Fig. 3 for adjusting the turboregulator forconstant engine power independent of altitude. An aneroid control valveI32 is disposed in the bleed line I4 from the pressure regulator I3. Thevalve I32 is movable by a sealed bellows I33 in response to variationsin atmospheric pressure transmitted to said bellows through conduit I35,and is designed to close at a particular altitude, e. g., 20,000 feet,and to open at lower altitudes to provide a vent bleed connection to theregulator in which the bleed opening decreases with increase of altitudeand vice versa. The discharge side of the valve I32 is connected to anevacuated chamber I34 which is maintained at a constant pressure by avacuum pump I36. The regulator is vented to an evacuated chamber insteadof to the atmosphere in order to obtain a sufficient bleed through theline I4 and valve I32 to obtain the desired pressure drop across therestricted orifice I2 to the pressure regulator at the lower altitudes.

With the above arrangement the valve I32 provides a maximum bleed fromthe pressure connection to the regulator atlow altitudes and this bleedgradually decreases as the altitude increases. Therefore, ,in the caseof the boost regulator, with a given setting of the regulator, themanifold pressure will decrease with in-, crease of altitude and thevalve I32 is so profiled that constant engine power is maintained for agiven setting of the regulator. Similarly, in combination with aturbo-regulator, the operation of valve I32 results in a decreasingturbine nozzle box pressure with increase in altitude for a givensetting Of the regulator, and the valve I32 is so designed that aconstant engine power is maintained.

The power control valve I38, illustrated in Fig. '7, is connected inparallel with the aneroid valve I32 and is designed to open to provide avent bleed from the turbo-regulator through the restricted orifice I40.The power valve I33 is supported from a diaphragm I33 and is springurgedtoward a closed position. One side of the diaphragm I39 is incommunication with the anti-detonant supply tank 46 and the other sideis vented to the evacuated chamber I34 through a restricted orifice I40when the solenoid valve I42 is open. As in the previous modifications,the tank 46 is subjected to the engine intake manifold pressure througha check valve 56. The valve I33 is designed to be opened by the combinedmanifold and anti-detonant pressure acting against the diaphragm I33 atnormal high However, since the turbine expower engine operation. Then ifemergency power is desired, a suitable manual switch may be closed toenergize the solenoid of valve I42 or as illustrated, power controllever 23 may be operated to energize this solenoid by closure of switchcontacts I and I43 above a predetermined engine power setting. Thereuponvalve I42 opens to provide a bleed path from the line I4 through thevalve I33. As a result of this additional bleed through the line I4 fromthe pressure regulator, the regulator repositions itself for directlyincreasing the manifold pressure in the system of Fig. l, or forincreasing the nozzle box pressure in the system of Fig. 3. At the sametime, the metering valve 43 is designed to be opened by manifoldpressure, whereupon water is discharged into the combustible mixturethrough the nozzles at the carburetor adapter. In'other words, whenabove-normal engine power is desired, solenoid valve I42 is opened toprovide a vent bleed to the pressure regulator, the regulator operatesto reposition itself and increase the engine power, and the accompanyingdischarge of anti-detonant into the combustible mixture inhibitsdetonation at this increased power. When the supply of anti-detonant isexhausted power control valve I33 closes as in the previousmodifications, thereby reducing the engine power to its normal valueeven though the solenoid valve I42 is still open.

In order to increase the normal detonationfree power range of aninternal combustion engine, it is common practice to gradually increasethe fuel-air ratio above a predetermined power, e. g., by means of aso-called carburetor enrichment-valve. Apparently, the extra fuel has acooling efiect in the engine and, in addition, slowsup combustion,thereby inhibiting detonation. In any case, by increasing the fuel-airratio at the higher engine powers, more power may be obtained from theengine before detonation occurs. It is possible to operate the engine atthese higher'powers without increasing the fuel-air ratio if ananti-detonant such as, water is injected into the combustible mixture.Fig. 8 illustrates such a further application of an antidetonationinjection system. The engine has not carburetor has been illustratedwhich relates to means for automatically enriching the fuelair ratio athigher engine powers.

In Fig. 8 (as in Figures 1 and 3) the water or other anti-detonantsupply tank 43 is subjected to engine manifold pressure through the lineI48 and check valve 53 and is adapted to discharge the anti-detonantthrough the metering valve 43, line I43, and the discharge nozzles atthe carburetor adapter. A solenoid valve I50 is disposed in line I43 andthis valve is urged by a spring to a position for closing the line I43.As illustrated, a diaphragm I33 through conduits I32 and I54respectively, has its opposite sides connected across the restrictionI35 in line I43, whereby upon flow of anti-detonant through line I43,the diaphragm I33 is subjected to the pressure differential across therestriction I65 to urge the diaphragm to the left, as viewed in thedrawing. A plunger element I64 is carried by the diaphragm I60 and isarranged to cooperate with a conventional carburetor automaticenrichment valve I66 forming part of a conventional carburetor toprevent this valve from opening when combined anti-detonant and manifoldpressure is applied to the diaphragm I33 through line I54. The detailsof the power en- 13 richment valve and the associated carburetorstructure form no part of the present invention and the invention may beused with any other equivalent means for automatically increasing thefuel-air ratio at higher engine powers.

As illustrated in Fig. 8, conventional carburetor fuel-metering jets I68and I10 are disposed in the fuel line I12 through which the carburetorcontrols the fuel flow in proportion to the air flow. An automaticenrichment valve I66 is disposed in parallel with the jet I10. The valveI66 is urged to a closed position by a spring I14 and is connected to adiaphragm I16. One side of the diaphragm I16 is subjected to the fuelpressure on the upstream side of the jet I68 through a passage I18 forurging the valve in an opening direction. The other side of thediaphragm I16 is subjected to the fuel pressure on the downstream sideof the jet I68. That is, the diaphragm I16 is subjected to a pressuredifferential proportional to the magnitude of the fuel flow as measuredby the pressure differential across orifice I68. Accordingly, the valveI66 is designed to open above a predetermined fuel flow in the fuel lineI12 to an extent determined by the magnitude of said flow, therebyincreasing the fuel-air ratio as the engine power is increased byproviding a fuel passage in parallel with jet I10. As previouslyexplained, the reason for thus enriching the combustible mixture is toinhibit detonation at the higher engine powers.

With the arrangement illustrated in Fig. 8, detonation may also beinhibited at these higher engine powers by opening the solenoid valveI50, whereupon the anti-detonant is discharged into the intake system,the metering valve 48 having previously been opened by the manifoldpressure. As soon as the solenoid valve I50 opens, the combined waterand manifold pressure in the line I48 acts against the diaphragm I60which thereupon flexes to position the plunger or stop member I64against the enrichment valve I66 to prevent opening of this valve.

The circuit on the solenoid valve I50 may be controlled by a substitutemanual switch or by a switch comprising contacts II and I53 adapted tobe closed by an engine power control lever, which, for example, maycomprise the control lever 26 of the power control regulator I8 or I8illustrated in Figures 1 and 3 respectively. The switch contacts I 5|and I53 are arranged to be closed by the control lever 26 when thislever is set for a predetermined engine power at which either thefuel-air ratio of the combustible mixture must be increased or anantidetonant must be added to the combustible mixture in order toinhibit engine detonation. Closure of switch contacts I5I and I53results in energization of the solenoid to open the valve I50, whereuponthe anti-detonant is discharged into the engine induction system and theplunger I 64 prevents the enrichment valve I66 from opening, all asalready described. If the supply of anti-detonant should becomeexhausted during this operation, then the pressure differential acrossrestriction I 65 immediately decreases, since the restriction I65 offersmuch less resistance to the flow of a gas, whereupon the plunger I64 nolonger prevents opening movement of the power enrichment valve I66.

If the water or other anti-detonant is only used to inhibit detonationin lieu of enriching the combustible mixture, then the quantity ofanti-detonant required is quite small, and therefore, metering thissmall quantity of anti-detonant is not entirely essential. Thus, themetering valve 48 could be dispensed with, and the bellows 58, insteadof controlling this valve, could be arranged to close a switch in thecircuit of solenoid I50 above a predetermined engine manifold pressureto effect introduction of the antidetonant into the engine inductionsystem. Such an arrangement is illustrated inFigure 8A in which thebellows 58 is responsive to the engine manifold pressure and is adaptedto close switch contacts I SI and I53 to energize the solenoid and openthe valve I50 above a predetermined manifold pressure. Figure 8A isotherwise similar to Figure 8. With either the arrangement of Figure 8or Figure 8A the engine may be operated in its normal high power rangeby introducing an antidetonant into the engine induction system toinhibit detonation instead of inhibiting detonation by increasing thefuelair ratio of the combustible mixture.

Instead of using the engine intake manifold pressure as the motivatingforce for discharging the water or other anti-detonant from the tank 46,a pump may be used for this purpose in any of the previously describedmodifications. Such an arrangement is illustrated in Fig. 9 in which theanti-detonant supply tank 46 is vented to the atmosphere through a checkvalve I80. A pump I82 is disposed in the discharge line I84 from thetank 46 and an electric motor I86 is drivably connected to the pump. Thecircuit for the motor I86 includes a switch I88 which may be controlledby the control lever 26 of the pressure regulator I8. In this way thepump I82 may be operated whenever the control lever is set for apressure corresponding to an engine power at which injection of anantidetonant into the engine induction system is desired. The meteringvalve 48 is disposed in the line I 84 and is responsive to the engineintake manifold pressure for regulating the flow of anti-detonantthrough line I89 to the discharge nozzles as in the previousmodifications. Also, in order to prevent operation of the pump I82 whenthe tank 46 is empty, a pair of spaced electric contacts I90 aredisposed in the conduit I 84 on the inlet side of the pump. It has beenfound that when the conduit space between the contacts I90 is filledwith water or other anti-detonant, that the electric resistance betweenthe contacts is lowered sufficiently to permit the operation of aso-called micro-ampere relay I92 having a switch I94 in the circuit ofthe motor I86. Therefore, when the supply of anti-detonant is exhausted,the relay I92 is de-energized and the switch I94 opens the circuit tothe pump motor I82.

Any one of the previously described power control valves 66, I20 or I38may be controlled by the pressure in line I89 for opening a restrictedvent such as 16, I24 or I40 in the pressure line 14 for automaticallyincreasing the engine power when anti-detonant is being discharged intothe engine induction system. Instead, however, Fig. 9 illustrates asolenoid-operated power control valve I95 which, when operated, opens arestricted vent in the line 14 to the atmosphere through restrictedorifice I88 to the pressure regulator. The solenoid I95 is controlled bya switch I96 of a so-called micro-ampere relay I91 in circuitwithcontacts I98, disposed in spaced relation in the conduit I 89. With thisarrangement, when the anti-detonant is being discharged through theconduit I89 into the en gine induction system, the relay I91 isenergized amazes to close its switch I96, whereupon the solenoid valveI95 opens the restricted vent in the line 14 to the pressure regulator.The pressure regulator thereupon automatically operates to increase theengine power as previously described. When the supply of water or otheranti-detonant is exhausted, the relay I81 is de-energized and thesolenoid valve I95 closes the vent in line 14 to the pressure regulator,whereupon the regulator automatically operates to reduce the enginepower output. Obviously, the solenoid-operated power control valve I95with its control circuit could be substituted for any of the fluidpressure-operated power control valves 66, I20 or I38 previouslydescribed.

While we have described our invention in detail in its present preferredembodiment, it will be obvious to those-skilled in the art, afterunderstanding our invention, that various changes and modifications maybe made therein without departing from the spirit or scope thereof. Weaim in the appended claims to cover all such modifications and changes.

We claim as our invention:

1. A' systemfor inhibiting detonation in an internal combustion enginecomprising means automatically operative in response to an increase inengine power above a predetermined value for effecting introduction ofan anti-detonant into the engine, and means automatically operative whenthe supply of anti-detonant is exhausted for effecting a reduction inthe engine power.

2. In an internal combustion engine, means automatically operative inresponse to an increase in the engine power above a predetermined valuefor effecting introduction of an antidetonant into said engine, saidmeans including a valve automatically adjustable with engine power forvarying the rate of introduction of said anti-detonant into said engine,and means automatically responsive to depletion of said antidetonantsupply for reducing the power of said engine.

I 3. In an internal combustion engine, means automatically responsive toan increase in the engine power above a predetermined value foreffecting introduction of an anti-detonant into said engine, thepressure differential across a portion of the engine induction systemproviding the motivating force for introducing said antidetonant, andmeans automatically operative when the supply of anti-detonant isexhausted for effecting a reduction in the engine power.

4. In an internal combustion engine, an engine power regulatorresponsive to a pressure associated with the power of said engine, meansoperable to provide a restricted bleed for said regulator responsivepressure, means automatically responsive to an increase in the enginepower above a predetermined value for introducing an antidetonant intosaid engine, and means operable to close said restricted bleed when saidsupply of anti-detonant is exhausted to effect a reduction in the powerof said engine.

5. In an internal combustion engine, an engine power regulatorresponsive to a pressure associated with the power of said engine andadapted to automatically increase the engine power upon a decrease insaid regulator responsive pressure.

and vice versa, valve means adapted when open 4 to provide a restrictedbleed for said regulator responsive pressure to effect a reduction inthe pressure to said regulator, means automatically responsive to anincrease in the engine power above a predetermined value for introducingan anti-detonant into said engine, and means adapted to automaticallyopen said valve to effect a further increase in power of said enginesubstantially simultaneously with initiation of said anti-detonantintroduction.

6. In an internal combustion engine, an engine power regulatorresponsive to a pressure associated with the power of said engine andadapted to automatically increase the engine power upon a decrease insaid regulator responsive pressure and vice versa, valve means adaptedwhen open to provide a restricted bleed in the pressure connection tosaid regulator to effect a reduction in the pressure to said regulator,means automatically responsive to an increase in the engine power abovea predetermined value for introducing an anti-detonant into said engine,and means adapted to automatically open said valve to effect a furtherincrease in power of said engine substantially simultaneously withinitiation of said anti-detonant introduction and adapted toautomatically close said valve when the supply of anti-detonant isexhausted to eficct a reduction in the power of said engine.

'7. In an internal combustion engine, an engine power regulatorresponsive to the intake manifold pressure and adapted to automaticallyincrease the engine power upon a decrease in manifold pressure and viceversa, valve means adapted when open to provide a restricted bleed inthe manifold pressure connection to said regulator, means automaticallyresponsive to an increase in the engine manifold pressure above apredetermined value for effecting introduction of an anti-detonant intothe engine induction system, and means operable to close said valve whenthe supply of said anti-detonant is exhausted to effect a reduction inthe power of said engine.

8. In an internal combustion engine having an engine exhaustdriventurbo-supercharger, a turbo-regulator responsive to a pressurevariable with the engine power output and adapted to automaticallyincrease the engine power upon a decrease in said pressure and viceversa, valve means adapted to open a restricted bleed of the pressureconnection to said regulator, means automatically responsive to anincrease in the engine power above a predetermined value for dischargingan anti-detonant into the engine induction system, and means operable toclose said valve when the supply of said anti-detonant is exhausted toeffect a reduction in the power of said engine.

9. In an internal combustion engine, an engine power regulatorresponsive to a pressure associated with the power of said engine andadapted to automatically increase the engine power upon a decrease insaid regulator responsive pressure and vice versa, a restricted orificein the pressure connection to said regulator, a valve adapted when opento provide a restricted bleed through said orifice thereby effecting adrop in pressure to said regulator, means automatically respon sive toan increase in the engine power above a predetermined value forintroducing an antidetonant into said engine, and means operable toclose said valve when the supply of said antidetonant is exhausted andto provide a temporary by-pass pressure connection around saidrestricted orifice in order to effect a quick reduction in the power ofsaid engine.

10. In an internal combustion engine, an engine power regulatorresponsive to a pressure .is-

76 sociated with the power of said engine and combustible mixture,

adapted to automatically increase the engine power upon a decrease insaid regulator responsive pressure and vice versa, a restricted orificein the pressure connection to said regulator, a valve adapted when opento provide a restricted bleed through said orifice thereby effecting adrop in pressure to said regulator, means automatically responsive to anincrease in the engine power above a predetermined value for introducingan .anti-detonant into said engine, means operable to close said valvewhen the supply of said antidetonant is exhausted and to provide atemporary by-pass pressure connection around said restricted orifice inorder to effect'a quick reduction in the power of said engine, and meansto close said by-pass after said engine power has been reduced.

11. In an internal combustion engine, means adjustable to vary the poweroutput of said engine, means automatically operative in response to anincrease in the power output of said engine above a predetermined valuefor effecting introduction of an anti-detonant into said engine, andmeans automatically operative when the supply of said anti-detonant isexhausted for adjusting said first named means to effect a reduction inthe power output of said engine.

12. In an internal combustion engine, means adjustable to vary the poweroutput of said engine, means providing a passage for supplying ananti-detonant into said engine, means adapted to automatically efiectintroduction oi said antidetonant through said passage into said engineupon an increase in the power of said engine above a predeterminedvalue, and means adapted to automatically adjustsaid first-named meansto effect a further increase in the power of said engine substantiallysimultaneously with initiation of said anti-detonant introduction.

13. In an internal combustion engine, means adjustable to vary the poweroutput of said engine, means providing a passage for supplying ananti-detonant into said engine, means adapted to automatically eiTectintroduction of said antidetonant through said passage into said engineupon an increase in the power of said engine above a predeterminedvalue, and means adapted to automatically adjust said first-named meansto efiecta further increase in the power of said engine substantiallysimultaneously with initiation of said anti-detonant introduction, saidlastnamed means including means adapted upon stoppage of saidanti-detonant introduction to automatically adjust said first-namedmeans'to reduce the engine power.

14. In an internal combustion engine, means adjustable to vary the poweroutput of said 011- operative in response to an-increase in the poweroutput of said engine above a predetermined value for efiectingintroduction of said anti-detonant into said engine by forcing saidanti-detonant gine, fluid passage means for supplying an antiv detonantto said engine, means automatically said engine, and means adaptedautomatically 'to at least partially prevent fuel-air-ratic-increasingmovement of said first-named means substantially simultaneously withinitiation or said anti-detonant introduction.

16. In an internal combustion engine, first means movable above apredetermined engine power to increase the fuel-air ratio of the enginecombustible mixture, second means operable for effecting introduction ofan anti-detonant into said engine, and third means automaticallyoperable substantially simultaneously with initiation of saidanti-detonant introduction for at least partially preventing movement ofsaid first means to a fuel-air-ratio-increasing position.

17. In an internal combustion engine, means adjustable to vary the poweroutput of said engine, means providing a passage for supplying ananti-detonant into said engine, means adapted to automatically efi'ectintroduction of said antidetonant through said passage into said engineupon an increase in the power of said engine above a predeterminedvalue, and means adapted to automatically adjust said first-named meansto effect a further increase in the power of said engine substantiallysimultaneously with initiation of said anti-detonant introduction, saidlastnamed means being responsive to the pressure of said anti-'detonantin said passage.

18. An anti-detonant flow control system for internal combustion engineshaving associated therewith a liquid line for supplying antidetonant tosaid engine, comprising electrically operated means in said liquid lineoperable when energized to cause anti-detonant to flow to said engine,an-electric" circuit including said electrically operated means, andcontrol mechanism in said circuit operable in response to the manifoldpressure in said engine to prevent energizatlon of said electricallyoperated means at manifold pressures below a predetermined value and tocause energization thereof when the manifold pressure rises to saidpredetermined value.

19. In an internal combustion engine; an engine power regulator; apassageway communicating with said regulator for transmitting thereto afluid under pressure indicative of the engine power output, saidregulator" being operative to increase or decrease said power outputupon a decrease or increase respectively in the pressure of said fluidat said regulatorj means automatically operative upon an increaseintheengine power output above a, predetermined value for effectingintroduction of an anti-detonant in said engine and for causing a dropin the pressure of said fluid transmitted thru saidpassageway to saidregulator whereupon said regulator is automatically operative to effecta further increase in said engine power; and a pressure-rewvlief valveautomatically operative to limit the under pressure through said passagemeans into said engine, and means automatically operative -in responseto a reduction in pressure within said passage means for adjusting saidfirst named means to efiect a reduction in the power output of saidengine.

15. In an internal combustion engine, means normally movable above apredetermined engine power to increase the fuel-air ratio of the engineable above said predetermined engine power for eilecting introduction ofan anti-detonant into and means selectively operv crease in the enginepower magnitude of said pressure drop.

' 20. In an internal combustion engine; an engine power regulatorresponsive to a fluid pressure'associated with the power of said engineand adapted to automatically increase or decrease the engine power upona decrease or increase respectively in said pressure at said regulator;a passageway communicating with said regulator and including a valve anda seriallyconnected restriction, said valve when? open permitting fiuidflow through said restriction so that the fluid pressure drop acrosssaid restrictionreduces lator; means automatically responsive to' aninabove a predetermined the magnitude of said pressure at said reguvaluefor effecting introduction. of an antidetonant into said engine and foropening said valve; and a pressure relief valve connected in parallelwith said restriction so that said pressure relief valve limits themagnitude of the fluid pressure drop across said restriction.

21. Control apparatus for controlling the pressure of air supplied tothe fuel system of an internal combustion engine in which means areprovided for injecting an anti-detonant into the fuel system whenabnormal power is needed, said apparatus comprising an adjustable meansfor selecting the pressure of air and having a wide range ofuninterrupted adjustment including a range of pressures suflicientlyhigh that operation of the engine. without injection of the antidetonantwould cause injury to the engine, and means responsive to the pressureof the antidetonant effective in the absence thereof to limit said rangeof adjustment.

22. Control apparatus for adjusting the intake manifold pressure of aninternal combustion engine and for injecting an anti-detonant into theengine, comprising adjustable meas for selecting the pressure, saidmeans having a first range of adjustment effective when theanti-detonant is not being injected into the engine and a further rangecalling for higher pressures when the antidetonant is being used, andmeans responsive to the injection of the anti-detonant into the engineand operative when the supply of antidetonant fails to override the saidadjustable means if in said further range for said higher pressures.

23. Control apparatus for controlling the pressure of air supplied tothe fuel system of an internal combustion engine in which meansincluding a source of fluid anti-detonant under pressure are providedfor injecting an antidetonant into the fuel system when abnormal poweris needed, said apparatus comprising an adjustable means for selectingthe pressure of air and having a wide range of uninterrupted adjustmentincluding a range of pressures sufliciently high that operation of theengine without anti-detonant injection would cause injury to the engine,and means adapted to respond to the differential between the pressure ofsaid source of anti-detonant and the pressure within said fuel systemfor limiting said range of adjustment in the absence of theanti-detonant.

24. In an internal combustion engine; means adjustable to vary the poweroutput of said engine; means adjustable to vary the ratio of fuel andair supplied to the engine; means automatically operative in response toan increase in the power output of said engine above a predeterminedvalue for effecting introduction of an anti; detonant into said engine;means for efl'ecting ply of anti-detonant should 20 adjustment of saidfuel-air ratio adjustable means to a relatively low fuel-air ratioduring introduction of said anti-detonant and, if the supply ofanti-detonant should become exhausted during engine operation above saidpredetermined value of power output, for effecting adjustment of saidadjustable means to a relativelyhigh fuelair ratio; and meansautomatically operative when the supply of anti-detonant becomesexhausted during engine operation above said predetermined value ofpower output for efiecting adjustment of said first-named means toreduce said power output.

25. In an internal combustion engine; means adjustable to vary the poweroutput of said engine; means for controlling the ratio of fuel and airsupplied to the engine, said means including a valve disposed in a fuelpassage and effective to increase or decrease the ratio of said fuel toair upon movement of said valve in an opening or closing directionrespectively; means automatically operative in response to an increasein the power output of said engine above a predetermined value foreffecting introduction of an anti-detonant into said engine; meansautomatically operative for positioning said valve in a relatively lowfuel-air ratio position during introduction of said anti-detonant and,if the supbecome exhausted during engine operation above saidpredetermined value of power output, for positioning said valve in arelatively high fuel-air ratio position; and means automaticallyoperative when the supply of anti-detonant becomes exhausted duringengine operation above said predetermined value of power output foreffecting adjustment of said first-named means to reduce said power output.

FRANCIS J. WIEGAND. EROLD F. PIERCE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

